Variable speed epicyclic gear transmission



1944- .LP. POPOFF VARIABLE SPEED EPICYCLIC GEAR TRANSMISSION Filed March 17, 1945 [n yen for epicyclic train, andfloat inginternahgear ii.

2,363301 wmannnisnnnnmercyouoon) A GEFiFHTE The invention relates xto ran epioyc'lic ,vgear transmission :for amotor vehioles "(or ro ther ma chines) designed ito cgive zinfinitesimal variation of the, velocity .i-ratioro'f :the tdrivenisshaftcirelative :to the driving engine shaftriand alls'o itoigive van automatic regulation/of zthe Lfload Hon itihe engine "whichisxsubjected to1eonstantly'waryinggradient loading.

accompanying "drawing in -which ii iignrefll Lissa vertical: section of'the :medhanismflfigureflZ =is an end view of the Lmeohanismw'featur'ing thegsvorm :gearing, :the hypoid :bevl tgearing, "the electric ,motorlandthe-zaxialzthrnstibearingilli. i g "The transmission is' a -:eorn'b'ination not iaamaln 1 epicyclio gear train rot in -:;certain velocity ratio and an auxiliary -epicyc1ic pgear train ot a adiflerent velooity ratio.

(An epicyclic .;:gear train is 1deflne'd i as a train of gear wheels in which there "is a relative mo :tion between "two "or more of sithe :axes :of'the :wheels constituting the train: QIt can-consist of a trainof gear wheelsiknownuas: csun andxplane tary wheels; sun, planetary wheels and internal In myinvention vanyconeuof theseiorms of epicyelic gear trains, (or -a icombination of them, can be i used and moreover 'any one rneniberf or these epicyclic gear atria-ins can the fused has a gear wheel; differential :gear whens) driver member, 1. e., connected 'to the source :of power, as a, driven member, i. 'e.,-conneeted to the driven shaft and as a floatingoracontrolllng member, i. e.; it floats (-rotates*Ireely) when the driverrotates :and the adrivenlis stationary and by controlling its speed the driven member can be forced to IOl'zflitfiiflt various '"speeds with re spect to the driver and wice-versa'. I a In :my dra-wingqItuse a sun, planetary minions and internal gearrwheel arrangement, the de- 1 scription of which follows: v i

The main epicyclic gear train consists era sun gear wheel? keyed to the transmission shaft 20, ,planetaryxpinions 3 rotating son *pins 4 attached to the iiywheel i, known aslt'he larm -ofithe The auxiliary eplcyclio z gear train consists :similarly of asun twhee'lfillwkeyedito the transmission shaft 20, planetary gpinions lilrotating on the pins M attached tothetlonghubbed wheel 15 known as thearm oftthe :ep'icycl ic train, and

roams. rotary- 2 2) by 'an auxiliary source 0'1 power such 'as "an -enrgine sorian eleotric motor -10. Thiselectricfimo- Ltor lis :regeneratively *coupled to the vehicles dynamo sand storage batteries which means that the welectriclmotorwcan be used as :a generator to send eleotric current back into the storage 'batiteries and :can be utilized engine starter. Arspider frame ZI fastened to theflywheel 5 is operatively: coupled by 1 means of another one way clutch to the shypoid gear wheel I! in mesh 'withithe hypoidpinion I! keyed to the shaft 26 of the :worm and motor. -A plateclutohM slidapplying "the pedal or handle 23.

ing on splines milled on the hyp'oid gear hubflB can connect solidly spider frame 2l to "hypoid gear l-8,ithns bridging the one way clutch H by Transmission shaft Zllenters gearbox 24 which contains one set of forward gears with -1:"1 ratio, one set of .reversegears witha conventionalratio and there isflalso a neutral position;

The electric motor I'D, forming withthe -vehicle s generator a regenerative unit which means that the electric motor "can be used as "a generator to send electric; current back into the storage batteries supplies "the power "for the auxiliary epicyclicgear train and maintains a predetermined constant speed until all members, ofthe transmission reach synchronous rotativim with respect to the engine. Whenan increase of the engine speed above the electric motors speed is effectedthe one way clutch ll looks the spider up to the twpoid gear 18 and from then on the powerot the auxiliary *epicyclio gear train is provided by the engine. Under this condition the engine drivesalso the electric motor as a generator. Thisarrangement enables the transmission to work automatically at quiet synchronous speed for all speeds of the engine. Tostart the engine from the electric motor l0, plate clutch 22 is pressedinto action and power flows from electrie motor In to hypoid gearing floating internal gear jwheel v2L6 operative-1y conpled to floating wheel 5 ;-by means of a one way i (or also known as free wheelingl "clutchl. On

the extended hub of wheel 1 5 is keyeda worm gear 8 which is rotatedbythe wormi9 gdriven as follows:

19, l*8-t0 plate clutch 22, to spiderrZl andto flywheel 5. Before applying the starting Clutch 22fcare must be taken that the gears in boi 24 arein neutral position. "I'hetransmission works At predetermined speeds oi the driving shaft lyand the electric motor 10, the throttle pedal having been released, the driven shaft-20 is stationary. Q'Ifhe flywheel 5 with the planetary gpinions .3 and the floating wheel 6 rotate and their respective speeds as well the speedof the members of the auxiliary epicyclic gear'train can be calculated from the following algebraical relations:

framework.

Then

The velocity ratio R of the epicyclic gear train,

- when the arm is fixed, is

Product of teeth in driving wheels Product of teeth in driven wheels or expressed in terms of speeds,

.Then

'C'A 5 f or mam epicyclic gear train and so C' A V -.2 for auxiliary epicyclic gear tram From these expressions I write,

.o=115A -.5s 2

C' =l.2A .2S (3) Under running conditions c'=c also s= s and A1=600, therefore:

When shaft is at rest S=0 and 4:480 and from Equations (2) and (3):

These results illustrate that when the engine makes 480 R. P. M. or less the driven shaft 20 will be at rest. Now, pressing the throttle pedal of the engine, this will tend to increase the speed of the control wheel 6 until it equalizes with the speed of the auxiliary control wheel I6 after which the process of actual driving work starts, i. e., as wheel 6 is not allowed to increase its speed above thatof wheel IS, a shunting of power to the driven shaft 20 takes place and it starts rotating. The immediate effect of this is to reduce the speed of wheel l8 (since the auxiliary driving member is kept at constant speed) which in turn will reduce the speed of wheel 6 and this in turn will further increase the speed of driven shaft 20,- this cycle of operation, analogous to the electromagnetic building up in the dynamo machinery, going on until steady conditions are reached, acontinued furtherdepressing of the throttle pedal will continue increasing the speed of the driven shaft 20 until it reaches the speed of driving shaft l, i. e., synchronous speed of all the members of the transmission is established. From Equations (2), (3) and (4) values of the speeds of the driving and control members can be obtained for different speeds of the driven shaft 2.

Thus when:

S A C e y 600 600 600 Also: V S i A C It will be evident to persons skilled in the art that the variable speed epicyclic gear transmission inventedby me may incorporate different combinations and arrangements of:

1. Gear ratios.

, 2..Types 'of epicyclic gear drives such as external orv internal planetary drives or differential epicyclic gearing. u

Therefore I do not limit my invention to the specifications given, above and-to the drawing attached herewith "but to all different combinations of variable speedepicyclic gear transmissions' consisting of two or more epicyclic gear trains which are interconnected by means of one way clutches and arranged towork on the building up" principle of my invention or as stated inmy claims herewith. I I

1'. A'planetary variable speed transmission for motor vehicles consisting ofa main epicyclic gear train'of a certain velocity ratio andof an auxiliaryepicyclic gear train of a different velocity ratio, each epicyclic gear train consistingof a driving member, adriven member and a controlling member, said driving members connected to a. main and an auxiliary source of motive. power respectively, said driven members connected to the driven shaft of the transmission, said floating members connected to one another by means of a one-way clutch, a hypoid bevel gearing and a plate clutch, means operatively connecting said auxiliary source of power to the vehicle's engine through said bevel gearing and plate clutch to start the engine from rest.

2. A variable speed planetary transmission for automotive vehicles consisting of a mainplanetary gear train Of a certain gear ratio and of an.

ber of the'auxiliary planetary gear-train being a long hubbed arm wheel and a number of plane tary pinions rotating on pins attached to the long hubbed arm wheel revolving on, and co-axial.

with, the driven transmission shaft alined with the driving engine shaft; said driven members of both. planetary gear trains are made of sun gears keyed to the driven transmission shaft alined with the driving engine shaft; said controlling members of both planetary gear trains are made of internal gear wheels revolving on, and co-axial with, the driven transmission shaft alined with the driving engine shaft; one freewheeling-one-way clutch coupling automatically said controlling gear wheels to equal speeds after a predetermined engine speed is being exceeded; whereby, the driven transmission shaft commences rotating; a high-emciency non-reversible worm gear wheel keyed to said long hubbed arm wheel of the auxiliary planetary gear train, a ,WOI'm in mesh with said worm gear and driven from an auxiliary electric motor at constant speed; a hypoid bevel gearingembodying a bevel gear wheel rotating on, and co-axial with, said long hubbed arm wheel, and a bevel pinion offset from said bevel gear wheel and keyed to the shaft of the auxiliary electric motor; an annular spider or cylindrical frame firmly secured to the engine flywheel and extending co-axially over the hub of said hypoid gear wheel, a second "free-wheeling-one-way" clutch coupling automatically said spider frame with said hypoid gear wheel to equal speeds after the engine speed exceeds the speed of the worm gear as provided by the electric motor, whereby, all members of the transmission rotate at synchronous speed for all engine speeds. 3. A variable speed transmission for motor vehicles consisting of a main differential epicyclic gear train of a certain gear ratio and an auxiliary differential epicyclic gear train of a different gear ratio, each differential epicyclic gear train consisting iof a driving ;member alined with the engine shaft, of a driven member alined with the engine shaft and of a controlling member alined with the engine shaft; means operatively connecting said driving member of the main differential epicyclic gear train to the shaft of an engine; a non-reversible high efliciency worm gearing and an auxiliary source of power, means operatively applying said auxiliary power through said worm gearing to the driving member of the auxiliary differential epicyclic gear train at constant speed; means operatively connecting said driven members of both differential epicyclic gear trains to a driven shaft; means operatively connecting said controlling member of the main differential epicyclic gear train to said controlling member of the auxiliary epicyclic gear train through a free-wheeling one way clutch, whereby at stand still of the driven shaft, with the engine running below a predetermined speed, said controlling gear wheels are not locked to equal speed, and when the predetermined engine speed is exceeded, automatic locking of the controlling wheels takes place and the driven shaft starts rotating.

JOHN PETER POPOF'F. 

